Recently, multimedia broadcasting services, such as digital broadcast, radio broadcasting, Digital Multimedia Broadcasting (DMB), Internet broadcasting, a digital movie, a Digital Versatile Disc (DVD), and moving image contents has been actively provided to audiences.
FIG. 1 is a block diagram illustrating a conventional multimedia transmission system. Referring to FIG. 1, the conventional multimedia transmission system 100 includes a packetizer 110 to packetize a plurality of input Elementary Streams (ESs) (ES 1, ES 2, ES 3 . . . ES n), a multiplexer 120 to multiplex the packetized data, and a transmitter 130 to transmit the multiplexed data to a medium 140.
Operation of the conventional multimedia transmission system 100 is described below referring to FIG. 2.
FIG. 2 illustrates an example of conventional packetization of ES data. Referring to
FIGS. 1 and 2, ES data (210) is inputted to the packetizer 110 of the conventional multimedia transmission system 100. Then, the packetizer 110 adds a header 220 to the ES data 210 to packetize the data, and the multiplexer 120 multiplexes the packetized data and transmits the same to the medium 140 via a transmitter 130.
However, when multimedia transmission with Moving Pictures Expert Group 2 Transport Stream (MPEG-2 TS) is performed, different ESs are not simultaneously included in a single Packetized Elementary Streams (PES) and transmitted after being packetized into TSs having different Packet Identifications (PIDs) from each other.
Thus, in the case of media service, because the service mostly provides a single audio object and a single video object, there is not a significant problem in independent packetization of each ES, but packetization of multimedia including a plurality of objects may have a problem of a high rate of incurring overhead.
To solve the above-mentioned problem in the case of the multimedia including a plurality of objects, a conventional Flex MUX packet scheme which can packetize a plurality of ESs into a single packet is used.
FIG. 3 illustrates a process of packetization of ES through a conventional Flex MUX scheme. Referring to FIG. 3, first, an SL header 320 corresponding to an ES 310 is added to the ES 310 and the ES 310 is then packetized. Specifically, since the Flux MUX scheme can packetize ESs having different encoding methods and frame rates into a single packet, Flux MUX aggregates ESs including the SL header 320 generated before Flux MUX, adds a Flux MUX header 330, and then packetizes the ES.
In this case, the SL header 320 includes an identifier to identify different SL packets, replay time of each SL packet, and the like. The Flux MUX header 330 includes information for generated Flux MUX data.
However, as described above, in the conventional Flux MUX scheme, since the SL header 320 includes excessive information to identify respective ES data, many bytes are assigned, thereby having a problem that data transmission is not efficient. Therefore, a packetization technique which can generate a header with small capacity is required.